Dr. Heidi Lyn, assistant professor of psychology at The University of Southern Mississippi Gulf Coast, co-authored a paper recently published by the journal Frontiers in Psychology showing the comparison of communication by baby apes and humans, which implicates the theory of how language evolved in humans.

In the study, “A Cross-Species Study of Gesture and Its Role in Symbolic Development: Implications for the Gestural Theory of Language Evolution,” Lyn partnered with researchers at the University of California, Los Angeles, and the Great Ape Trust in Des Moines, Iowa. The research team tracked the gestures of a child from the age of eight months to two years, as well as a chimpanzee and bonobo who were observed for nearly four years.

Using video analysis, the researchers found that all three subjects make similar gestures when interacting with caregivers. These gestures include reaching out arms and pointing with fingers and heads. As the experiment progressed, the child began communicating more vocally, while the apes used visual communication in the form lexigrams. The study explained this as “the first indication of a distinctive human pathway to language.”